Methods to communicate parameters across multiple component carriers of a carrier aggregation for sidelink communication

ABSTRACT

Embodiments of a User Equipment (UE) and methods of communication are generally described herein. The UE may select one or more of the component carriers (CCs) of a carrier aggregation, and may transmit a sidelink synchronization signal (SLSS) and a physical sidelink broadcast channel (PSBCH) on the one or more selected CCs. The UE may encode the PSBCH to include a plurality of parameters related to the sidelink operation, wherein the plurality of parameters are to be propagated across all of the CCs of the plurality of CCs for the sidelink operation. The UE may transmit one or more physical sidelink shared channels (PSSCHs) in accordance with the carrier aggregation, and further in accordance with the plurality of parameters propagated across the plurality of CCs.

PRIORITY CLAIM

This application claims priority under 35 USC 119(e) to U.S. ProvisionalPatent Application Ser. No. 62/653,729, filed Apr. 6, 2018, which isincorporated herein by reference in its entirety.

TECHNICAL FIELD

Embodiments pertain to wireless networks. Some embodiments relate tocellular communication networks including 3GPP (Third GenerationPartnership Project) networks, 3GPP LTE (Long Term Evolution) networks,3GPP LTE-A (LTE Advanced) networks, New Radio (NR) networks, and 5Gnetworks, although the scope of the embodiments is not limited in thisrespect. Some embodiments relate to sidelink synchronization. Someembodiments relate to carrier aggregation.

BACKGROUND

Efficient use of the resources of a wireless network is important toprovide bandwidth and acceptable response times to the users of thewireless network. However, often there are many devices trying to sharethe same resources and some devices may be limited by the communicationprotocol they use or by their hardware bandwidth. Moreover, wirelessdevices may need to operate with both newer protocols and with legacydevice protocols.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a functional diagram of an example network in accordance withsome embodiments;

FIG. 1B is a functional diagram of another example network in accordancewith some embodiments;

FIG. 2 illustrates a block diagram of an example machine in accordancewith some embodiments;

FIG. 3 illustrates a user device in accordance with some aspects;

FIG. 4 illustrates a base station in accordance with some aspects;

FIG. 5 illustrates an exemplary communication circuitry according tosome aspects,

FIG. 6 illustrates an example of a radio frame structure in accordancewith some embodiments;

FIG. 7A and FIG. 7B illustrate example frequency resources in accordancewith some embodiments;

FIG. 8 illustrates the operation of a method of communication inaccordance with some embodiments; and

FIG. 9 illustrates example synchronization options in accordance withsome embodiments.

DETAILED DESCRIPTION

The following description and the drawings sufficiently illustratespecific embodiments to enable those skilled in the art to practicethem. Other embodiments may incorporate structural, logical, electrical,process, and other changes. Portions and features of some embodimentsmay be included in, or substituted for, those of other embodiments.Embodiments set forth in the claims encompass all available equivalentsof those claims.

FIG. 1A is a functional diagram of an example network in accordance withsome embodiments. FIG. 1B is a functional diagram of another examplenetwork in accordance with some embodiments. In references herein, “FIG.1” may include FIG. 1A and FIG. 1B. In some embodiments, the network 100may be a Third Generation Partnership Project (3GPP) network. In someembodiments, the network 150 may be a 3GPP network. In a non-limitingexample, the network 150 may be a new radio (NR) network. It should benoted that embodiments are not limited to usage of 3GPP networks,however, as other networks may be used in some embodiments. As anexample, a Fifth Generation (5G) network may be used in some cases. Asanother example, a New Radio (NR) network may be used in some cases. Asanother example, a wireless local area network (WLAN) may be used insome cases. Embodiments are not limited to these example networks,however, as other networks may be used in some embodiments. In someembodiments, a network may include one or more components shown in FIG.1A. Some embodiments may not necessarily include all components shown inFIG. 1A, and some embodiments may include additional components notshown in FIG. 1A. In some embodiments, a network may include one or morecomponents shown in FIG. 1B. Some embodiments may not necessarilyinclude all components shown in FIG. 1B, and some embodiments mayinclude additional components not shown in FIG. 1B. In some embodiments,a network may include one or more components shown in FIG. 1A and one ormore components shown in FIG. 1B. In some embodiments, a network mayinclude one or more components shown in FIG. 1A, one or more componentsshown in FIG. 1B and one or more additional components.

The network 100 may comprise a radio access network (RAN) 101 and thecore network 120 (e.g., shown as an evolved packet core (EPC)) coupledtogether through an S1 interface 115. For convenience and brevity sake,only a portion of the core network 120, as well as the RAN 101, isshown. In a non-limiting example, the RAN 101 may be an evolveduniversal terrestrial radio access network (E-UTRAN). In anothernon-limiting example, the RAN 101 may include one or more components ofa New Radio (NR) network. In another non-limiting example, the RAN 101may include one or more components of an E-UTRAN and one or morecomponents of another network (including but not limited to an NRnetwork).

The core network 120 may include a mobility management entity (MME) 122,a serving gateway (serving GW) 124, and packet data network gateway (PDNGW) 126. In some embodiments, the network 100 may include (and/orsupport) one or more Evolved Node-B's (eNBs) 104 (which may operate asbase stations) for communicating with User Equipment (UE) 102. The eNBs104 may include macro eNBs and low power (LP) eNBs, in some embodiments.

In some embodiments, the network 100 may include (and/or support) one ormore Next Generation Node-B's (gNBs) 105. In some embodiments, one ormore eNBs 104 may be configured to operate as gNBs 105. Embodiments arenot limited to the number of eNBs 104 shown in FIG. 1A or to the numberof gNBs 105 shown in FIG. 1A. In some embodiments, the network 100 maynot necessarily include eNBs 104. Embodiments are also not limited tothe connectivity of components shown in FIG. 1A.

It should be noted that references herein to an eNB 104 or to a gNB 105are not limiting. In some embodiments, one or more operations, methodsand/or techniques (such as those described herein) may be practiced by abase station component (and/or other component), including but notlimited to a gNB 105, an eNB 104, a serving cell, a transmit receivepoint (TRP) and/or other. In some embodiments, the base stationcomponent may be configured to operate in accordance with a New Radio(NR) protocol and/or NR standard, although the scope of embodiments isnot limited in this respect. In some embodiments, the base stationcomponent may be configured to operate in accordance with a FifthGeneration (5G) protocol and/or 5G standard, although the scope ofembodiments is not limited in this respect.

In some embodiments, one or more of the UEs 102, gNBs 105, and/or eNBs104 may be configured to operate in accordance with an NR protocoland/or NR techniques. References to a UE 102, eNB 104, and/or gNB 105 aspart of descriptions herein are not limiting. For instance, descriptionsof one or more operations, techniques and/or methods practiced by a gNB105 are not limiting. In some embodiments, one or more of thoseoperations, techniques and/or methods may be practiced by an eNB 104and/or other base station component.

In some embodiments, the UE 102 may transmit signals (data, controland/or other) to the gNB 105, and may receive signals (data, controland/or other) from the gNB 105. In some embodiments, the UE 102 maytransmit signals (data, control and/or other) to the eNB 104, and mayreceive signals (data, control and/or other) from the eNB 104. Theseembodiments will be described in more detail below.

The MME 122 is similar in function to the control plane of legacyServing GPRS Support Nodes (SGSN). The MME 122 manages mobility aspectsin access such as gateway selection and tracking area list management.The serving GW 124 terminates the interface toward the RAN 101, androutes data packets between the RAN 101 and the core network 120. Inaddition, it may be a local mobility anchor point for inter-eNBhandovers and also may provide an anchor for inter-3GPP mobility. Otherresponsibilities may include lawful intercept, charging, and some policyenforcement. The serving GW 124 and the MME 122 may be implemented inone physical node or separate physical nodes. The PDN GW 126 terminatesan SGi interface toward the packet data network (PDN). The PDN GW 126routes data packets between the EPC 120 and the external PDN, and may bea key node for policy enforcement and charging data collection. It mayalso provide an anchor point for mobility with non-LTE accesses. Theexternal PDN can be any kind of IP network, as well as an IP MultimediaSubsystem (IMS) domain. The PDN GW 126 and the serving GW 124 may beimplemented in one physical node or separated physical nodes.

In some embodiments, the eNBs 104 (macro and micro) terminate the airinterface protocol and may be the first point of contact for a UE 102.In some embodiments, an eNB 104 may fulfill various logical functionsfor the network 100, including but not limited to RNC (radio networkcontroller functions) such as radio bearer management, uplink anddownlink dynamic radio resource management and data packet scheduling,and mobility management.

In some embodiments, UEs 102 may be configured to communicate OrthogonalFrequency Division Multiplexing (OFDM) communication signals with an eNB104 and/or gNB 105 over a multicarrier communication channel inaccordance with an Orthogonal Frequency Division Multiple Access (OFDMA)communication technique. In some embodiments, eNBs 104 and/or gNBs 105may be configured to communicate OFDM communication signals with a UE102 over a multicarrier communication channel in accordance with anOFDMA communication technique. The OFDM signals may comprise a pluralityof orthogonal subcarriers.

The S1 interface 115 is the interface that separates the RAN 101 and theEPC 120. It may be split into two parts: the S1-U, which carries trafficdata between the eNBs 104 and the serving GW 124, and the S1-MME, whichis a signaling interface between the eNBs 104 and the MME 122. The X2interface is the interface between eNBs 104. The X2 interface comprisestwo parts, the X2-C and X2-U. The X2-C is the control plane interfacebetween the eNBs 104, while the X2-U is the user plane interface betweenthe eNBs 104.

In some embodiments, similar functionality and/or connectivity describedfor the eNB 104 may be used for the gNB 105, although the scope ofembodiments is not limited in this respect. In a non-limiting example,the S1 interface 115 (and/or similar interface) may be split into twoparts: the S1-U, which carries traffic data between the gNBs 105 and theserving GW 124, and the S1-MME, which is a signaling interface betweenthe gNBs 104 and the MME 122. The X2 interface (and/or similarinterface) may enable communication between eNBs 104, communicationbetween gNBs 105 and/or communication between an eNB 104 and a gNB 105.

With cellular networks, LP cells are typically used to extend coverageto indoor areas where outdoor signals do not reach well, or to addnetwork capacity in areas with very dense phone usage, such as trainstations. As used herein, the term low power (LP) eNB refers to anysuitable relatively low power eNB for implementing a narrower cell(narrower than a macro cell) such as a femtocell, a picocell, or a microcell. Femtocell eNBs are typically provided by a mobile network operatorto its residential or enterprise customers. A femtocell is typically thesize of a residential gateway or smaller and generally connects to theuser's broadband line. Once plugged in, the femtocell connects to themobile operator's mobile network and provides extra coverage in a rangeof typically 30 to 50 meters for residential femtocells. Thus, a LP eNBmight be a femtocell eNB since it is coupled through the PDN GW 126.Similarly, a picocell is a wireless communication system typicallycovering a small area, such as in-building (offices, shopping malls,train stations, etc.), or more recently in-aircraft. A picocell eNB cangenerally connect through the X2 link to another eNB such as a macro eNBthrough its base station controller (BSC) functionality. Thus, LP eNBmay be implemented with a picocell eNB since it is coupled to a macroeNB via an X2 interface. Picocell eNBs or other LP eNBs may incorporatesome or all functionality of a macro eNB. In some cases, this may bereferred to as an access point base station or enterprise femtocell. Insome embodiments, various types of gNBs 105 may be used, including butnot limited to one or more of the eNB types described above.

In some embodiments, the network 150 may include one or more componentsconfigured to operate in accordance with one or more 3GPP standards,including but not limited to an NR standard. The network 150 shown inFIG. 1B may include a next generation RAN (NG-RAN) 155, which mayinclude one or more gNBs 105. In some embodiments, the network 150 mayinclude the E-UTRAN 160, which may include one or more eNBs. The E-UTRAN160 may be similar to the RAN 101 described herein, although the scopeof embodiments is not limited in this respect.

In some embodiments, the network 150 may include the MME 165. The MME165 may be similar to the MME 122 described herein, although the scopeof embodiments is not limited in this respect. The MME 165 may performone or more operations or functionality similar to those describedherein regarding the MME 122, although the scope of embodiments is notlimited in this respect.

In some embodiments, the network 150 may include the SGW 170. The SGW170 may be similar to the SGW 124 described herein, although the scopeof embodiments is not limited in this respect. The SGW 170 may performone or more operations or functionality similar to those describedherein regarding the SGW 124, although the scope of embodiments is notlimited in this respect.

In some embodiments, the network 150 may include component(s) and/ormodule(s) for functionality for a user plane function (UPF) and userplane functionality for PGW (PGW-U), as indicated by 175. In someembodiments, the network 150 may include component(s) and/or module(s)for functionality for a session management function (SMF) and controlplane functionality for PGW (PGW-C), as indicated by 180. In someembodiments, the component(s) and/or module(s) indicated by 175 and/or180 may be similar to the PGW 126 described herein, although the scopeof embodiments is not limited in this respect. The component(s) and/ormodule(s) indicated by 175 and/or 180 may perform one or more operationsor functionality similar to those described herein regarding the PGW126, although the scope of embodiments is not limited in this respect.One or both of the components 170, 172 may perform at least a portion ofthe functionality described herein for the PGW 126, although the scopeof embodiments is not limited in this respect.

Embodiments are not limited to the number or type of components shown inFIG. 1B. Embodiments are also not limited to the connectivity ofcomponents shown in FIG. 1B.

In some embodiments, a downlink resource grid may be used for downlinktransmissions from an eNB 104 to a UE 102, while uplink transmissionfrom the UE 102 to the eNB 104 may utilize similar techniques. In someembodiments, a downlink resource grid may be used for downlinktransmissions from a gNB 105 to a UE 102, while uplink transmission fromthe UE 102 to the gNB 105 may utilize similar techniques. The grid maybe a time-frequency grid, called a resource grid or time-frequencyresource grid, which is the physical resource in the downlink in eachslot. Such a time-frequency plane representation is a common practicefor OFDM systems, which makes it intuitive for radio resourceallocation. Each column and each row of the resource grid correspond toone OFDM symbol and one OFDM subcarrier, respectively. The duration ofthe resource grid in the time domain corresponds to one slot in a radioframe. The smallest time-frequency unit in a resource grid is denoted asa resource element (RE). There are several different physical downlinkchannels that are conveyed using such resource blocks. With particularrelevance to this disclosure, two of these physical downlink channelsare the physical downlink shared channel and the physical down linkcontrol channel.

As used herein, the term “circuitry” may refer to, be part of, orinclude an Application Specific Integrated Circuit (ASIC), an electroniccircuit, a processor (shared, dedicated, or group), and/or memory(shared, dedicated, or group) that execute one or more software orfirmware programs, a combinational logic circuit, and/or other suitablehardware components that provide the described functionality. In someembodiments, the circuitry may be implemented in, or functionsassociated with the circuitry may be implemented by, one or moresoftware or firmware modules. In some embodiments, circuitry may includelogic, at least partially operable in hardware. Embodiments describedherein may be implemented into a system using any suitably configuredhardware and/or software.

FIG. 2 illustrates a block diagram of an example machine in accordancewith some embodiments. The machine 200 is an example machine upon whichany one or more of the techniques and/or methodologies discussed hereinmay be performed. In alternative embodiments, the machine 200 mayoperate as a standalone device or may be connected (e.g., networked) toother machines. In a networked deployment, the machine 200 may operatein the capacity of a server machine, a client machine, or both inserver-client network environments. In an example, the machine 200 mayact as a peer machine in peer-to-peer (P2P) (or other distributed)network environment. The machine 200 may be a UE 102, eNB 104, gNB 105,access point (AP), station (STA), user, device, mobile device, basestation, personal computer (PC), a tablet PC, a set-top box (STB), apersonal digital assistant (PDA), a mobile telephone, a smart phone, aweb appliance, a network router, switch or bridge, or any machinecapable of executing instructions (sequential or otherwise) that specifyactions to be taken by that machine. Further, while only a singlemachine is illustrated, the term “machine” shall also be taken toinclude any collection of machines that individually or jointly executea set (or multiple sets) of instructions to perform any one or more ofthe methodologies discussed herein, such as cloud computing, software asa service (SaaS), other computer cluster configurations.

Examples as described herein, may include, or may operate on, logic or anumber of components, modules, or mechanisms. Modules are tangibleentities (e.g., hardware) capable of performing specified operations andmay be configured or arranged in a certain manner. In an example,circuits may be arranged (e.g., internally or with respect to externalentities such as other circuits) in a specified manner as a module. Inan example, the whole or part of one or more computer systems (e.g., astandalone, client or server computer system) or one or more hardwareprocessors may be configured by firmware or software (e.g.,instructions, an application portion, or an application) as a modulethat operates to perform specified operations. In an example, thesoftware may reside on a machine readable medium. In an example, thesoftware, when executed by the underlying hardware of the module, causesthe hardware to perform the specified operations.

Accordingly, the term “module” is understood to encompass a tangibleentity, be that an entity that is physically constructed, specificallyconfigured (e.g., hardwired), or temporarily (e.g., transitorily)configured (e.g., programmed) to operate in a specified manner or toperform part or all of any operation described herein. Consideringexamples in which modules are temporarily configured, each of themodules need not be instantiated at any one moment in time. For example,where the modules comprise a general-purpose hardware processorconfigured using software, the general-purpose hardware processor may beconfigured as respective different modules at different times. Softwaremay accordingly configure a hardware processor, for example, toconstitute a particular module at one instance of time and to constitutea different module at a different instance of time.

The machine (e.g., computer system) 200 may include a hardware processor202 (e.g., a central processing unit (CPU), a graphics processing unit(GPU), a hardware processor core, or any combination thereof), a mainmemory 204 and a static memory 206, some or all of which may communicatewith each other via an interlink (e.g., bus) 208. The machine 200 mayfurther include a display unit 210, an alphanumeric input device 212(e.g., a keyboard), and a user interface (UI) navigation device 214(e.g., a mouse). In an example, the display unit 210, input device 212and UI navigation device 214 may be a touch screen display. The machine200 may additionally include a storage device (e.g., drive unit) 216, asignal generation device 218 (e.g., a speaker), a network interfacedevice 220, and one or more sensors 221, such as a global positioningsystem (GPS) sensor, compass, accelerometer, or other sensor. Themachine 200 may include an output controller 228, such as a serial(e.g., universal serial bus (USB), parallel, or other wired or wireless(e.g., infrared (IR), near field communication (NFC), etc.) connectionto communicate or control one or more peripheral devices (e.g., aprinter, card reader, etc.).

The storage device 216 may include a machine readable medium 222 onwhich is stored one or more sets of data structures or instructions 224(e.g., software) embodying or utilized by any one or more of thetechniques or functions described herein. The instructions 224 may alsoreside, completely or at least partially, within the main memory 204,within static memory 206, or within the hardware processor 202 duringexecution thereof by the machine 200. In an example, one or anycombination of the hardware processor 202, the main memory 204, thestatic memory 206, or the storage device 216 may constitute machinereadable media. In some embodiments, the machine readable medium may beor may include a non-transitory computer-readable storage medium. Insome embodiments, the machine readable medium may be or may include acomputer-readable storage medium.

While the machine readable medium 222 is illustrated as a single medium,the term “machine readable medium” may include a single medium ormultiple media (e.g., a centralized or distributed database, and/orassociated caches and servers) configured to store the one or moreinstructions 224. The term “machine readable medium” may include anymedium that is capable of storing, encoding, or carrying instructionsfor execution by the machine 200 and that cause the machine 200 toperform any one or more of the techniques of the present disclosure, orthat is capable of storing, encoding or carrying data structures used byor associated with such instructions. Non-limiting machine readablemedium examples may include solid-state memories, and optical andmagnetic media. Specific examples of machine readable media may include:non-volatile memory, such as semiconductor memory devices (e.g.,Electrically Programmable Read-Only Memory (EPROM), ElectricallyErasable Programmable Read-Only Memory (EEPROM)) and flash memorydevices; magnetic disks, such as internal hard disks and removabledisks; magneto-optical disks; Random Access Memory (RAM); and CD-ROM andDVD-ROM disks. In some examples, machine readable media may includenon-transitory machine readable media. In some examples, machinereadable media may include machine readable media that is not atransitory propagating signal.

The instructions 224 may further be transmitted or received over acommunications network 226 using a transmission medium via the networkinterface device 220 utilizing any one of a number of transfer protocols(e.g., frame relay, internet protocol (IP), transmission controlprotocol (TCP), user datagram protocol (UDP), hypertext transferprotocol (HTTP), etc.). Example communication networks may include alocal area network (LAN), a wide area network (WAN), a packet datanetwork (e.g., the Internet), mobile telephone networks (e.g., cellularnetworks), Plain Old Telephone (POTS) networks, and wireless datanetworks (e.g., Institute of Electrical and Electronics Engineers (IEEE)802.11 family of standards known as Wi-Fi®, IEEE 802.16 family ofstandards known as WiMax®), IEEE 802.15.4 family of standards, a LongTerm Evolution (LTE) family of standards, a Universal MobileTelecommunications System (UMTS) family of standards, peer-to-peer (P2P)networks, among others. In an example, the network interface device 220may include one or more physical jacks (e.g., Ethernet, coaxial, orphone jacks) or one or more antennas to connect to the communicationsnetwork 226. In an example, the network interface device 220 may includea plurality of antennas to wirelessly communicate using at least one ofsingle-input multiple-output (SIMO), multiple-input multiple-output(MIMO), or multiple-input single-output (MISO) techniques. In someexamples, the network interface device 220 may wirelessly communicateusing Multiple User MIMO techniques. The term “transmission medium”shall be taken to include any intangible medium that is capable ofstoring, encoding or carrying instructions for execution by the machine200, and includes digital or analog communications signals or otherintangible medium to facilitate communication of such software.

FIG. 3 illustrates a user device in accordance with some aspects. Insome embodiments, the user device 300 may be a mobile device. In someembodiments, the user device 300 may be or may be configured to operateas a User Equipment (UE). In some embodiments, the user device 300 maybe arranged to operate in accordance with a new radio (NR) protocol. Insome embodiments, the user device 300 may be arranged to operate inaccordance with a Third Generation Partnership Protocol (3GPP) protocol.The user device 300 may be suitable for use as a UE 102 as depicted inFIG. 1, in some embodiments. It should be noted that in someembodiments, a UE, an apparatus of a UE, a user device or an apparatusof a user device may include one or more of the components shown in oneor more of FIGS. 2, 3, and 5. In some embodiments, such a UE, userdevice and/or apparatus may include one or more additional components.

In some aspects, the user device 300 may include an applicationprocessor 305, baseband processor 310 (also referred to as a basebandmodule), radio front end module (RFEM) 315, memory 320, connectivitymodule 325, near field communication (NFC) controller 330, audio driver335, camera driver 340, touch screen 345, display driver 350, sensors355, removable memory 360, power management integrated circuit (PMIC)365 and smart battery 370. In some aspects, the user device 300 may be aUser Equipment (UE).

In some aspects, application processor 305 may include, for example, oneor more CPU cores and one or more of cache memory, low drop-out voltageregulators (LDOs), interrupt controllers, serial interfaces such asserial peripheral interface (SPI), inter-integrated circuit (I²C) oruniversal programmable serial interface module, real time clock (RTC),timer-counters including interval and watchdog timers, general purposeinput-output (IO), memory card controllers such as securedigital/multi-media card (SD/MMC) or similar, universal serial bus (USB)interfaces, mobile industry processor interface (MIPI) interfaces andJoint Test Access Group (JTAG) test access ports.

In some aspects, baseband module 310 may be implemented, for example, asa solder-down substrate including one or more integrated circuits, asingle packaged integrated circuit soldered to a main circuit board,and/or a multi-chip module containing two or more integrated circuits.

FIG. 4 illustrates a base station in accordance with some aspects. Insome embodiments, the base station 400 may be or may be configured tooperate as an Evolved Node-B (eNB). In some embodiments, the basestation 400 may be or may be configured to operate as a Next GenerationNode-B (gNB). In some embodiments, the base station 400 may be arrangedto operate in accordance with a new radio (NR) protocol. In someembodiments, the base station 400 may be arranged to operate inaccordance with a Third Generation Partnership Protocol (3GPP) protocol.It should be noted that in some embodiments, the base station 400 may bea stationary non-mobile device. The base station 400 may be suitable foruse as an eNB 104 as depicted in FIG. 1, in some embodiments. The basestation 400 may be suitable for use as a gNB 105 as depicted in FIG. 1,in some embodiments. It should be noted that in some embodiments, aneNB, an apparatus of an eNB, a gNB, an apparatus of a gNB, a basestation and/or an apparatus of a base station may include one or more ofthe components shown in one or more of FIGS. 2, 4, and 5. In someembodiments, such an eNB, gNB, base station and/or apparatus may includeone or more additional components.

FIG. 4 illustrates a base station or infrastructure equipment radio head400 in accordance with some aspects. The base station 400 may includeone or more of application processor 405, baseband modules 410, one ormore radio front end modules 415, memory 420, power management circuitry425, power tee circuitry 430, network controller 435, network interfaceconnector 440, satellite navigation receiver module 445, and userinterface 450. In some aspects, the base station 400 may be an EvolvedNode-B (eNB), which may be arranged to operate in accordance with a 3GPPprotocol, new radio (NR) protocol and/or Fifth Generation (5G) protocol.In some aspects, the base station 400 may be a Next Generation Node-B(gNB), which may be arranged to operate in accordance with a 3GPPprotocol, new radio (NR) protocol and/or Fifth Generation (5G) protocol.

In some aspects, application processor 405 may include one or more CPUcores and one or more of cache memory, low drop-out voltage regulators(LDOs), interrupt controllers, serial interfaces such as SPI, I²C oruniversal programmable serial interface module, real time clock (RTC),timer-counters including interval and watchdog timers, general purposeIO, memory card controllers such as SD/MMC or similar, USB interfaces,MIPI interfaces and Joint Test Access Group (JTAG) test access ports.

In some aspects, baseband processor 410 may be implemented, for example,as a solder-down substrate including one or more integrated circuits, asingle packaged integrated circuit soldered to a main circuit board or amulti-chip module containing two or more integrated circuits.

In some aspects, memory 420 may include one or more of volatile memoryincluding dynamic random access memory (DRAM) and/or synchronous dynamicrandom access memory (SDRAM), and nonvolatile memory (NVM) includinghigh-speed electrically erasable memory (commonly referred to as Flashmemory), phase change random access memory (PRAM), magneto-resistiverandom access memory (MRAM) and/or a three-dimensional cross-pointmemory. Memory 420 may be implemented as one or more of solder downpackaged integrated circuits, socketed memory modules and plug-in memorycards.

In some aspects, power management integrated circuitry 425 may includeone or more of voltage regulators, surge protectors, power alarmdetection circuitry and one or more backup power sources such as abattery or capacitor. Power alarm detection circuitry may detect one ormore of brown out (under-voltage) and surge (over-voltage) conditions.

In some aspects, power tee circuitry 430 may provide for electricalpower drawn from a network cable to provide both power supply and dataconnectivity to the base station 400 using a single cable. In someaspects, network controller 435 may provide connectivity to a networkusing a standard network interface protocol such as Ethernet. Networkconnectivity may be provided using a physical connection which is one ofelectrical (commonly referred to as copper interconnect), optical orwireless.

In some aspects, satellite navigation receiver module 445 may includecircuitry to receive and decode signals transmitted by one or morenavigation satellite constellations such as the global positioningsystem (GPS), Globalnaya Navigatsionnaya Sputnikovaya Sistema (GLONASS),Galileo and/or BeiDou. The receiver 445 may provide data to applicationprocessor 405 which may include one or more of position data or timedata. Application processor 405 may use time data to synchronizeoperations with other radio base stations. In some aspects, userinterface 450 may include one or more of physical or virtual buttons,such as a reset button, one or more indicators such as light emittingdiodes (LEDs) and a display screen.

FIG. 5 illustrates an exemplary communication circuitry according tosome aspects. Circuitry 500 is alternatively grouped according tofunctions. Components as shown in 500 are shown here for illustrativepurposes and may include other components not shown here in FIG. 5. Insome aspects, the communication circuitry 500 may be used for millimeterwave communication, although aspects are not limited to millimeter wavecommunication. Communication at any suitable frequency may be performedby the communication circuitry 500 in some aspects.

It should be noted that a device, such as a UE 102, eNB 104, gNB 105,the user device 300, the base station 400, the machine 200 and/or otherdevice may include one or more components of the communication circuitry500, in some aspects.

The communication circuitry 500 may include protocol processingcircuitry 505, which may implement one or more of medium access control(MAC), radio link control (RLC), packet data convergence protocol(PDCP), radio resource control (RRC) and non-access stratum (NAS)functions. Protocol processing circuitry 505 may include one or moreprocessing cores (not shown) to execute instructions and one or morememory structures (not shown) to store program and data information.

The communication circuitry 500 may further include digital basebandcircuitry 510, which may implement physical layer (PHY) functionsincluding one or more of hybrid automatic repeat request (HARQ)functions, scrambling and/or descrambling, coding and/or decoding, layermapping and/or de-mapping, modulation symbol mapping, received symboland/or bit metric determination, multi-antenna port pre-coding and/ordecoding which may include one or more of space-time, space-frequency orspatial coding, reference signal generation and/or detection, preamblesequence generation and/or decoding, synchronization sequence generationand/or detection, control channel signal blind decoding, and otherrelated functions.

The communication circuitry 500 may further include transmit circuitry515, receive circuitry 520 and/or antenna array circuitry 530. Thecommunication circuitry 500 may further include radio frequency (RF)circuitry 525. In an aspect of the disclosure, RF circuitry 525 mayinclude multiple parallel RF chains for one or more of transmit orreceive functions, each connected to one or more antennas of the antennaarray 530.

In an aspect of the disclosure, protocol processing circuitry 505 mayinclude one or more instances of control circuitry (not shown) toprovide control functions for one or more of digital baseband circuitry510, transmit circuitry 515, receive circuitry 520, and/or radiofrequency circuitry 525.

In some embodiments, processing circuitry may perform one or moreoperations described herein and/or other operation(s). In a non-limitingexample, the processing circuitry may include one or more componentssuch as the processor 202, application processor 305, baseband module310, application processor 405, baseband module 410, protocol processingcircuitry 505, digital baseband circuitry 510, similar component(s)and/or other component(s).

In some embodiments, a transceiver may transmit one or more elements(including but not limited to those described herein) and/or receive oneor more elements (including but not limited to those described herein).In a non-limiting example, the transceiver may include one or morecomponents such as the radio front end module 315, radio front endmodule 415, transmit circuitry 515, receive circuitry 520, radiofrequency circuitry 525, similar component(s) and/or other component(s).

One or more antennas (such as 230, 312, 412, 530 and/or others) maycomprise one or more directional or omnidirectional antennas, including,for example, dipole antennas, monopole antennas, patch antennas, loopantennas, microstrip antennas or other types of antennas suitable fortransmission of RF signals. In some multiple-input multiple-output(MIMO) embodiments, one or more of the antennas (such as 230, 312, 412,530 and/or others) may be effectively separated to take advantage ofspatial diversity and the different channel characteristics that mayresult.

In some embodiments, the UE 102, eNB 104, gNB 105, user device 300, basestation 400, machine 200 and/or other device described herein may be amobile device and/or portable wireless communication device, such as apersonal digital assistant (PDA), a laptop or portable computer withwireless communication capability, a web tablet, a wireless telephone, asmartphone, a wireless headset, a pager, an instant messaging device, adigital camera, an access point, a television, a wearable device such asa medical device (e.g., a heart rate monitor, a blood pressure monitor,etc.), or other device that may receive and/or transmit informationwirelessly. In some embodiments, the UE 102, eNB 104, gNB 105, userdevice 300, base station 400, machine 200 and/or other device describedherein may be configured to operate in accordance with 3GPP standards,although the scope of the embodiments is not limited in this respect. Insome embodiments, the UE 102, eNB 104, gNB 105, user device 300, basestation 400, machine 200 and/or other device described herein may beconfigured to operate in accordance with new radio (NR) standards,although the scope of the embodiments is not limited in this respect. Insome embodiments, the UE 102, eNB 104, gNB 105, user device 300, basestation 400, machine 200 and/or other device described herein may beconfigured to operate according to other protocols or standards,including IEEE 802.11 or other IEEE standards. In some embodiments, theUE 102, eNB 104, gNB 105, user device 300, base station 400, machine 200and/or other device described herein may include one or more of akeyboard, a display, a non-volatile memory port, multiple antennas, agraphics processor, an application processor, speakers, and other mobiledevice elements. The display may be an LCD screen including a touchscreen.

Although the UE 102, eNB 104, gNB 105, user device 300, base station400, machine 200 and/or other device described herein may each beillustrated as having several separate functional elements, one or moreof the functional elements may be combined and may be implemented bycombinations of software-configured elements, such as processingelements including digital signal processors (DSPs), and/or otherhardware elements. For example, some elements may comprise one or moremicroprocessors, DSPs, field-programmable gate arrays (FPGAs),application specific integrated circuits (ASICs), radio-frequencyintegrated circuits (RFICs) and combinations of various hardware andlogic circuitry for performing at least the functions described herein.In some embodiments, the functional elements may refer to one or moreprocesses operating on one or more processing elements.

Embodiments may be implemented in one or a combination of hardware,firmware and software. Embodiments may also be implemented asinstructions stored on a computer-readable storage device, which may beread and executed by at least one processor to perform the operationsdescribed herein. A computer-readable storage device may include anynon-transitory mechanism for storing information in a form readable by amachine (e.g., a computer). For example, a computer-readable storagedevice may include read-only memory (ROM), random-access memory (RAM),magnetic disk storage media, optical storage media, flash-memorydevices, and other storage devices and media. Some embodiments mayinclude one or more processors and may be configured with instructionsstored on a computer-readable storage device.

It should be noted that in some embodiments, an apparatus of the UE 102,eNB 104, gNB 105, machine 200, user device 300 and/or base station 400may include various components shown in FIGS. 2-5. Accordingly,techniques and operations described herein that refer to the UE 102 maybe applicable to an apparatus of a UE. In addition, techniques andoperations described herein that refer to the eNB 104 may be applicableto an apparatus of an eNB. In addition, techniques and operationsdescribed herein that refer to the gNB 105 may be applicable to anapparatus of a gNB.

FIG. 6 illustrates an example of a radio frame structure in accordancewith some embodiments. FIGS. 7A and 7B illustrate example frequencyresources in accordance with some embodiments. In references herein,“FIG. 7” may include FIG. 7A and FIG. 7B. It should be noted that theexamples shown in FIGS. 6-7 may illustrate some or all of the conceptsand techniques described herein in some cases, but embodiments are notlimited by the examples. For instance, embodiments are not limited bythe name, number, type, size, ordering, arrangement and/or other aspectsof the time resources, symbol periods, frequency resources, PRBs andother elements as shown in FIGS. 6-7. Although some of the elementsshown in the examples of FIGS. 6-7 may be included in a 3GPP LTEstandard, 5G standard, NR standard and/or other standard, embodimentsare not limited to usage of such elements that are included instandards.

An example of a radio frame structure that may be used in some aspectsis shown in FIG. 6. In this example, radio frame 600 has a duration of10 ms. Radio frame 600 is divided into slots 602 each of duration 0.5ms, and numbered from 0 to 19. Additionally, each pair of adjacent slots602 numbered 2i and 2i+1, where i is an integer, is referred to as asubframe 601.

In some aspects using the radio frame format of FIG. 6, each subframe601 may include a combination of one or more of downlink controlinformation, downlink data information, uplink control information anduplink data information. The combination of information types anddirection may be selected independently for each subframe 602.

Referring to FIGS. 7A and 7B, in some aspects, a sub-component of atransmitted signal consisting of one subcarrier in the frequency domainand one symbol interval in the time domain may be termed a resourceelement. Resource elements may be depicted in a grid form as shown inFIG. 7A and FIG. 7B.

In some aspects, illustrated in FIG. 7A, resource elements may begrouped into rectangular resource blocks 700 consisting of 12subcarriers in the frequency domain and the P symbols in the timedomain, where P may correspond to the number of symbols contained in oneslot, and may be 6, 7, or any other suitable number of symbols.

In some alternative aspects, illustrated in FIG. 7B, resource elementsmay be grouped into resource blocks 700 consisting of 12 subcarriers (asindicated by 702) in the frequency domain and one symbol in the timedomain. In the depictions of FIG. 7A and FIG. 7B, each resource element705 may be indexed as (k, l) where k is the index number of subcarrier,in the range 0 to N.M-1 (as indicated by 703), where N is the number ofsubcarriers in a resource block, and M is the number of resource blocksspanning a component carrier in the frequency domain.

In accordance with some embodiments, the UE 102 may be configured forsidelink operation in accordance with a carrier aggregation (CA) of aplurality of component carriers (CCs). The UE 102 may select one or moreof the CCs of the plurality of CCs for transmission of a sidelinksynchronization signal (SLSS) and a physical sidelink broadcast channel(PSBCH). The UE 102 may transmit the SLSS on each of the selected CCs,and in a subframe. The SLSS may be for synchronization by other UEs 102for the sidelink operation. The UE 102 may encode the PSBCH fortransmission on the one or more selected CCs in the same subframe usedfor transmission of the SLSS. The PSBCH may be encoded to include aplurality of parameters related to the sidelink operation. The pluralityof parameters may be propagated across all of the CCs of the pluralityof CCs for the sidelink operation. The UE 102 may encode one or morephysical sidelink shared channels (PSSCHs) for transmission inaccordance with the carrier aggregation. The PSSCHs may be encoded fortransmission on the plurality of CCs in accordance with the plurality ofparameters propagated across the plurality of CCs. These embodiments aredescribed in more detail below.

FIG. 8 illustrates the operation of a method of communication inaccordance with some embodiments. It is important to note thatembodiments of the methods 800, 900 may include additional or even feweroperations or processes in comparison to what is illustrated in FIG. 8.In addition, embodiments of the methods 800, 900 are not necessarilylimited to the chronological order that is shown in FIG. 8. Indescribing the method 800, reference may be made to one or more figures,although it is understood that the method 800 may be practiced with anyother suitable systems, interfaces and components.

In some embodiments, a UE 102 may perform one or more operations of themethod 800, but embodiments are not limited to performance of the method800 and/or operations of it by the UE 102. In some embodiments, anotherdevice and/or component may perform one or more operations of the method800. In some embodiments, another device and/or component may performone or more operations that may be similar to one or more operations ofthe method 800. In some embodiments, another device and/or component mayperform one or more operations that may be reciprocal to one or moreoperations of the method 800. In a non-limiting example, the gNB 105 mayperform an operation that may be the same as, similar to, reciprocal toand/or related to an operation of the method 800, in some embodiments.

It should be noted that one or more operations of the method 800 may bethe same as, similar to and/or reciprocal to one or more operations ofthe other method. In a non-limiting example, an operation of the method800 may include reception of an element (such as a frame, block, messageand/or other) by the UE 102, and an operation of another method mayinclude transmission of a same element (and/or similar element) by thegNB 105. In some cases, descriptions of operations and techniquesdescribed as part of the method 800 may be relevant to another method.

The method 800 and other methods described herein may refer to eNBs 104,gNBs 105 and/or UEs 102 operating in accordance with 3GPP standards, 5Gstandards, NR standards and/or other standards. However, embodiments arenot limited to performance of those methods by those components, and mayalso be performed by other devices, such as a Wi-Fi access point (AP) oruser station (STA). In addition, the method 800 and other methodsdescribed herein may be practiced by wireless devices configured tooperate in other suitable types of wireless communication systems,including systems configured to operate according to various IEEEstandards such as IEEE 802.11. The method 800 may also be applicable toan apparatus of a UE 102, an apparatus of an eNB 104, an apparatus of agNB 105 and/or an apparatus of another device described above.

It should also be noted that embodiments are not limited by referencesherein (such as in descriptions of the method 800 and/or otherdescriptions herein) to transmission, reception and/or exchanging ofelements such as frames, messages, requests, indicators, signals orother elements. In some embodiments, such an element may be generated,encoded or otherwise processed by processing circuitry (such as by abaseband processor included in the processing circuitry) fortransmission. The transmission may be performed by a transceiver orother component, in some cases. In some embodiments, such an element maybe decoded, detected or otherwise processed by the processing circuitry(such as by the baseband processor). The element may be received by atransceiver or other component, in some cases. In some embodiments, theprocessing circuitry and the transceiver may be included in a sameapparatus. The scope of embodiments is not limited in this respect,however, as the transceiver may be separate from the apparatus thatcomprises the processing circuitry, in some embodiments.

One or more of the elements (such as messages, operations and/or other)described herein may be included in a standard and/or protocol,including but not limited to Third Generation Partnership Project(3GPP), 3GPP Long Term Evolution (LTE), Fourth Generation (4G), FifthGeneration (5G), New Radio (NR) and/or other. Embodiments are notlimited to usage of those elements, however. In some embodiments, otherelements may be used, including other element(s) in a samestandard/protocol, other element(s) in another standard/protocol and/orother. In addition, the scope of embodiments is not limited to usage ofelements that are included in standards.

At operation 805 the UE 102 may receive control signaling. At operation810 the UE 102 may determine timing synchronization for sidelinkoperation. At operation 815 the UE 102 may determine one or moreparameters for the sidelink operation. At operation 820 the UE 102 maytransmit an SLSS. At operation 825 the UE 102 may transmit a PSBCH. Atoperation 830 the UE 102 may transmit a PSSCH.

In some embodiments, the control signaling may include parameters,information and/or other elements related to one or more of: sidelinkcommunication, sidelink operation, carrier aggregation, time resourcesfor transmission/reception of one or more elements, frequency resourcesfor transmission/reception of one or more elements, and/or other.

In some embodiments, the UE 102 may be configured for sidelink operationin accordance with a carrier aggregation (CA) of a plurality ofcomponent carriers (CCs). In some embodiments, the UE 102 may select oneor more of the CCs of the plurality of CCs for transmission of asidelink synchronization signal (SLSS) and a physical sidelink broadcastchannel (PSBCH). In some embodiments, the UE 102 may encode the SLSS fortransmission on each of the selected CCs in a subframe, wherein the SLSSis for synchronization by other UEs 102 for the sidelink operation. Insome embodiments, the UE 102 may encode the PSBCH for transmission oneach of the selected CCs in the same subframe used for transmission ofthe SLSS, wherein the PSBCH is encoded to include a plurality ofparameters related to the sidelink operation, wherein the plurality ofparameters is to be propagated across all of the CCs of the plurality ofCCs for the sidelink operation. In some embodiments, the UE 102 mayencode one or more physical sidelink shared channels (PSSCHs) fortransmission in accordance with the carrier aggregation, wherein thePSSCHs are encoded for transmission on the plurality of CCs inaccordance with the plurality of parameters propagated across theplurality of CCs.

Embodiments are not limited to selection of one or more of the CCs ofthe plurality of CCs for transmission of the SLSS and the PSBCH, and arealso not limited to selection of one of the CCs of the plurality of CCsfor transmission of the SLSS and the PSBCH. In some embodiments, atechnique, operation and/or method described herein that is based onselection of one of the CCs may be modified to be based on selection ofone or more of the CCs. In some embodiments, a technique, operationand/or method described herein that is based on selection of one or moreof the CCs may be modified to be based on selection of one of the CCs.

In some embodiments, the plurality of parameters related to the sidelinkoperation may include one or more of: a pre-configured bandwidthparameter of the one or more selected CCs, a pre-configuredtime-division duplexing (TDD) configuration parameter of the selectedCC, an in-coverage parameter, and a direct frame number (DFN) parameter.

In some embodiments, the UE 102 may determine timing synchronization forthe sidelink operation based on signaling received from the eNB 104. Insome embodiments, the UE 102 may derive the in-coverage parameter andthe DFN parameter based on the signaling received from the eNB 104. Insome embodiments, the UE 102 may determine timing synchronization forthe sidelink operation based on signaling received from another UE 102.In some embodiments, the UE 102 may determine the DFN parameter based onsignaling received from another UE 102.

In some embodiments, the UE 102 may determine timing synchronization forthe sidelink operation based on one or more received global navigationsatellite system (GNSS) signals. In some embodiments, the UE 102 maydetermine the DFN parameter based on the determined timingsynchronization for the sidelink operation and a pre-configured DFNoffset parameter.

In some embodiments, the bandwidth parameter may indicate a bandwidth interms of a number of resource blocks (RBs). In some embodiments, the TDDconfiguration parameter may indicate a TDD specific physical channelconfiguration. In some embodiments, the in-coverage parameter mayindicate whether the UE 102 is in Evolved Universal MobileTelecommunications Service (UMTS) Terrestrial Radio Area Network(E-UTRAN) coverage. In some embodiments, the DFN parameter for theselected CC may indicate a frame number in which the SLSS and SLBCH aretransmitted.

In some embodiments, the UE 102 may encode a master information block(MIB) for inclusion in the PSBCH. In some embodiments, the UE 102 mayencode the MIB to include the plurality of parameters related to thesidelink operation.

In some embodiments, the MIB may be a MasterInformationBlock-SL or aMasterInformationBlock-SL-V2X. In some embodiments, the plurality ofparameters related to the sidelink operation may include one or more of:a pre-configured sl-Bandwidth parameter for the selected CC, apre-configured tdd-config parameter for the selected CC, an in-coverageparameter, and a direct frame number (DFN) parameter.

In some embodiments, the UE 102 may encode the PSBCH to include an SLSSidentifier (SLSS-ID) that is to be propagated across all of the CCs ofthe plurality of CCs for the sidelink operation.

In some embodiments, the UE 102 may encode the PSBCH to include anindicator of whether the plurality of parameters is to be propagatedacross all of the CCs of the plurality of CCs for the sidelinkoperation.

In some embodiments, the UE 102 may select the CC for transmission ofthe SLSS and the PSBCH based on a tie-breaking rule that is based on ormore of: an SLSS CA indication flag, and one or more sidelink referencesignal received power (SL-RSRP) measurements of the CCs of the pluralityof CCs.

In some embodiments, the UE 102 may determine if reselection of the CCor transmission of the SLSS and the PSBCH is to be triggered when: acurrently used SLSS is lost at a used CC, all synchronization sourceswhich provide global navigation satellite system (GNSS) or networktiming are lost at the selected CC, or the UE 102 has not detected anSLSS source at the selected CC.

In some embodiments, the UE 102 may periodically reselect one of the CCsof the plurality of CCs for transmission of the SLSS and the PSBCH inaccordance with a period. In some embodiments, the period may bepreconfigured by a network, predefined by a protocol, or determinedautonomously based on SLSS detection statistics.

In some embodiments, the UE 102 may encode the SLSS for transmission on:the selected CC, or all of the CCs of a set-B that includes the selectedCC.

In some embodiments, the plurality of CCs may include a synchronizationset of CCs. In some embodiments, the UE 102 may encode the SLSS fortransmission in accordance with one of: selection of a subset of the CCsof the synchronization set, and periodic transmission of the SLSS on theCCs of the subset, selection of one of the CCs of the synchronizationset, and periodic transmission on the selected CC, cyclic switchingacross the CCs of the synchronization set, or iterative switching of CCgroups

In some embodiments, an apparatus of a UE 102 may comprise memory. Thememory may be configurable to store information related to the one ormore of the CCs. The memory may store one or more other elements and theapparatus may use them for performance of one or more operations. Theapparatus may include processing circuitry, which may perform one ormore operations (including but not limited to operation(s) of the method800 and/or other methods described herein). The processing circuitry mayinclude a baseband processor. The baseband circuitry and/or theprocessing circuitry may perform one or more operations describedherein, including but not limited to encoding of the SLSS and the PSBCH.The apparatus may include a transceiver to transmit the SLSS and thePSBCH. The transceiver may transmit and/or receive other blocks,messages and/or other elements.

FIG. 9 illustrates example elements in accordance with some embodiments.It should be noted that the examples shown in FIG. 9 may illustrate someor all of the concepts and techniques described herein in some cases,but embodiments are not limited by the examples. For instance,embodiments are not limited by the name, number, type, size, ordering,arrangement of elements (such as devices, operations, messages and/orother elements) shown in FIG. 9. Although some of the elements shown inthe examples of FIG. 9 may be included in a 3GPP LTE standard, 5Gstandard, NR standard and/or other standard, embodiments are not limitedto usage of such elements that are included in standards.

Sidelink based V2V communication was introduced in LTE R14. Thetechnology enables synchronization using various sidelinksynchronization sources including GNSS, eNB 104 and UEs 102. When the UE102 serves as a synchronization source it periodically once per 160 msbroadcasts sidelink synchronization signals (SLSS). The UE 102 servingas a synchronization source may: derive it its own timing from eNB104/GNSS; derive its timing from other UEs 102 deriving timing from GNSSor network; serve as an independent synchronization source; and/orother. The LTE R14 specification defines synchronization sourceselection rules in order to determine which synchronization sourceshould be used by the UE 102 as a synchronization reference. Thesynchronization procedure defined in LTE R14 is defined and operatesindependently per each component carrier. In LTE R15, the sidelinkcarrier aggregation was introduced.

In some embodiments, a modification of the LTE V2X sidelinksynchronization procedure developed in R14 may be performed. In somecases, such a modification may make the procedure suitable for sidelinkcarrier aggregation being enabled in LTE R15. One or more of thefollowing may be addressed in some of the embodiments described herein:UE SLSS/PSBCH transmission behavior in case of limited number of TXchains; PSBCH content modification; sidelink synchronization carrier andsidelink synchronization source (re)-selection; and/or other.

In some embodiments, one or more of the following may be used (as partof a multi-carrier sidelink synchronization procedure, in some cases,although the scope of embodiments is not limited in this respect):updated PSBCH content with new field to indicate whether sidelinksynchronization may be propagated across aggregated component carriers(CCs) for sidelink transmission/reception; additional tie-breaking ruleused in synchronization carrier selection procedure to selectsynchronization carrier with the most appropriate and reliablesynchronization source is specified; synchronization carrier andsidelink synchronization source (re)-selection procedure details,synchronization signal transmission behavior for the case when number ofSet-B CCs is larger than the number of TX chains; and/or other.

In some embodiments, higher layers can configure set of carrier(s)(Set-A) that can potentially be used as the synchronization carrier forthe potential carriers configured for Tx and Rx for CA. If this set isempty, Rel-14 independent synchronization may be used per carrier.Carriers can be aggregated if they use the same synchronizationreference (e.g. GNSS, or same eNB 104). If this set is non-empty: Set-Amust be a subset of the set of potential carriers configured for Tx andRx for CA; and UE 102 determines the available set of synchronizationcarriers (Set-B) as the subset of Set-A based on the carriers which theUE is currently aggregating. Within the Set-B of available set ofsynchronization carriers: if no potential synchronization carrier ispresent, Rel-14 behavior of independent synchronization per carrier isassumed; if only one potential synchronization carrier is present, UE102 may (and/or shall) use derive time/frequency of all the aggregatedcarriers from the synchronization reference of the synchronizationcarrier; if two or more potential synchronization carriers are present,various techniques may be used for how the UE 102 selects one of thecarrier to be used as the synchronization carrier.

In some embodiments, from the transmitting UE 102 perspective, a singlesynchronization reference is used for all aggregated carriers. From thereceiving UE 102 perspective, a single synchronization reference is usedfor reception of all aggregated carriers. If two or more potentialsynchronization carriers are present in Set-B, select the carrier inSet-B with highest Rel-14 priority sync reference. The carrier is notreselected unless synchronization is lost. Rel-14 procedure applies tothe selected carrier.

The UE 102 may be configured one of the following options: SLSS istransmitted (based on Rel-14 procedure) on selected sync carrier fromSet-B; SLSS is transmitted on all carriers from Set-B; and/or other.

Some embodiments may relate to physical sidelink broadcast channel(PSBCH) and/or sync propagation across carriers. In some embodiments, anew field in the PSBCH payload may be used. In order to extend sidelinksynchronization procedure for sidelink CA operation, the content ofPSBCH may be extended with an additional field. This new field mayindicate whether the UE 102 receiving this PSBCH and SLSS can propagatethe derived timing across aggregated component carriers. If this fieldis set (for instance), it may indicate that the UE 102 can propagatederived timing across aggregated CCs for transmission/reception ofPSBCH/SLSS or other sidelink channels (PSCCH/PSSCH). The new field(which may be an “SLSS CA Indication Flag,” a similar flag and/or otherparameter) may be used to inform receivers whether a given PSBCH/SLSS isapplicable for sidelink CA and thus synchronization can be propagatedacross CCs.

In some cases, this new indication may be needed in order to avoid wrongpropagation of the R14 timing across aggregated CCs (given that R14sidelink synchronization procedure is running independently per each CCand each R14 CC may potentially have different amount of synchronizationresources, different sync source priority rules, different timing,etc.). In general, it may be possible to align synchronizationconfiguration among R14 and R15 UEs 102, however at least for out ofcoverage operation it seems that additional indication may be desirable.

In some cases, this new field may be defined by using one of thereserved bits of the PSBCH payload (Sidelink Master InformationBlock—V2X). If inter component carrier synchronization configurationsare aligned across R14 and R15 UEs 102, the corresponding field may beeven preconfigured for R14 UEs 102—sync sources so that their SLSStiming can be also propagated by R15 UEs 102 across component carrier incase if both UE 102 types R14 and R15 operate on the samesynchronization carrier.

Some embodiments may be related to SLSS ID and/or PSBCH contentpropagation. In some cases of sidelink CA operation, the same timingderived from the reference synchronization source at component carrierserving as a synchronization reference may be used disregarding the SLSSID and PSBCH content propagation details. Some SLSS ID and PSBCH contentpropagation options are described below, and may be described elsewhereherein.

Regarding SLSS ID propagation, one or more of the following may beperformed in some embodiments: a same SLSS ID may be configured acrossaggregated component carriers; a same SLSS ID derived fromsynchronization source of reference synchronization carrier may bepropagated across aggregated component carriers; at each CC in whichsynchronization is propagated, the SLSS ID may be taken according topre-configuration information or derived independently based onsynchronization sources detected at corresponding CCs (e.g. followingsync source priority rules); and/or other.

In some embodiments, a PSBCH payload may include one or more of thefollowing fields: System bandwidth, TDD configuration, In-Coverage flag,DFN value, reserved field(s) and/or other. The first two fields (Systembandwidth, TDD configuration) are CC-specific and could not be modified.Each of the latter two PSBCH fields (In-Coverage flag and DFN value) maybe propagated following one or more of the following principles for SLSSID propagation: a same PSBCH field value is configured across aggregatedcomponent carriers; a same PSBCH field value is derived from referencesynchronization source propagated across aggregated component carriers;at each CC in which synchronization is propagated, the PSBCH field valueis derived based on pre-configuration information or derivedindependently based on synchronization sources detected from eachcorresponding CCs (e.g. following sync source priority rules).

In some embodiments, for sidelink CA, the synchronization carriers canbe represented by two sets: Set-A (set of potential sync carriers) andSet-B (subset of sync carriers determined by UE based on aggregatedCCs). In a non-limiting example, a synchronization carrier selectionprocedure may not necessarily specify UE behavior for cases in which twoor more carriers in Set-B have the same sync source priority. In somecases, including but not limited to those described in the aboveexample, in order to select synchronization source, one or moreadditional tie breaking rules may be used.

In some embodiments, such a tie breaking rule may utilize informationincluding but not limited to one or more of the following: a PSBCH “SLSSCA Indication Flag,” wherein an R15 UE may prioritize selection ofsynchronization CC which SLSS may be propagated across aggregatedcomponent carrier, an SL-RSRP measurement; wherein in some cases, the UE102 may apply SL-RSRP criteria to select synchronization CC (e.g. selectCC with higher SL-RSRP measured over DMRS of PSBCH or SLSS itself).

In some embodiments, a sidelink synchronization carrier reselectiontrigger may be used. In a previous agreement related to one or more 3GPPspecifications: “If two or more potential synchronization carriers arepresent in Set-B, UE selects the carrier in Set-B with the highestRel-14 priority sync reference. Carrier is not reselected unlesssynchronization is lost. Rel-14 procedure applies to the selectedcarrier”. According to this agreement, the event when “synchronizationis lost” should be specified in more details to clearly determine themoment, when synchronization carrier (Sync-CC) (re)selection should betriggered. The following options and/or additional option(s) arepossible. The following options may be referred to as “option 1,”“option 2,” and “option 3” for clarity, but such references are notlimiting. In option 1, sync-CC (re)-selection is triggered whencurrently used SLSS is lost at the used CC. In option 2, sync-CC(re)-selection is triggered when all synchronization sources whichprovide GNSS or network timing are lost at the selected sidelinksynchronization CC. In option 3, sync-CC (re)-selection is triggeredwhen UE has not detected any SLSS source at the selected sidelinksynchronization CC.

While option 1 may be most straightforward, it may result in significantscanning complexity and overhead caused by synchronization signaldetection that should be executed at each CC from Set-B. In option 3,the synchronization source (re)-selection overhead/complexity isminimized. However, in this case, the UE 102 may propagate for a verylong time synchronization signal originated by, for example, lowpriority independent synchronization source while synchronization sourceof higher priority (which use GNSS or network timing) may exist at othersynchronization carrier of Set B. Option 2 may provide a reasonablecompromise between Sync-CC reselection overhead and used synchronizationsource quality (which is associated with assigned priority), in somecases.

In some embodiments, if sync-CC reselection results in high prioritysynchronization source selection, the selected source may be kept asreference for a long time. However, if the UE 102 selects low prioritysync source or becomes independent synchronization source (i.e. syncsource with lowest priority), triggering of additional Sync-CCreselection may be used and/or needed to check whether higher prioritysidelink synchronization sources that exist at other Set-B CCs andsynchronization carrier should be (re)-selected.

In some embodiments, sync-CC (re)selection may be periodicallytriggered. Example alternatives (which may be referred to as“alternative 1” and “alternative” for clarity, without limitation) fordefinition of the sync-CC reselection period are given below. Additionalalternatives are possible, in some embodiments. In alternative 1, afixed sync carrier reselection period is used irrespective of the typeof currently used SLSS (i.e. sync source priority). In alternative 2,the sync carrier reselection period depends on synchronization sourcepriority currently used by the UE 102. In this case, the lower priorityof the used synchronization source, the more frequently sync-CCreselection is triggered and not triggered at all for some of the syncsource priority level (e.g. highest SLSS priority).

In some embodiments, the period may be preconfigured by the network,predefined by specification, determined by the UE 102 autonomously basedon SLSS detection statistics and/or based on one or more othertechniques. Additionally, if UEs 102 have multiple RX chains that arecapable to monitor SLSS on multiple CCs, the UE 102 may monitor multipleCCs for SLSS sync sources and may be able to reselect sync carrier ifthe higher priority sync source is detected.

In some cases, according to the previous agreements, the UE 102 may beconfigured to use one of the following SLSS transmission options (whichare referred to below as “option 1b” and “option 2b” for clarity,without limitation). In option 1b, the SLSS is transmitted (based onRel-14 procedure) on selected sync carrier from Set-B. In option 2b, theSLSS is transmitted on all carriers from Set-B.

In some scenarios, a number of UE TX chains (N_(TX)) may be less than anumber of synchronization carriers (N_(SYNC)). In this case, a UE 102with limited TX chain capabilities may need to switch TX chain in orderto transmit SLSS. One or more of the following TX PSBCH/SLSStransmission options (and/or other options) may be used. The options maybe referred to as “option 0c,” “option 1c,” “option 2c,” and “option 3c”for clarity, but such references are not limiting.

In option 0c, the UE 102 may transmit on N_(TX) out of N_(SYNC) CCs. Inthis case, the UE 102 may autonomously select N_(Tx) out of N_(SYNC) CCsand may periodically transmit SLSS on the selected N_(TX) CCs of the SetB.

In option 1c, the UE 102 may transmit on 1 out of N_(SYNC) CCs. In thiscase, the UE 102 may autonomously select one out of N_(SYNC) CCs and mayperiodically transmit SLSS on the selected CC of the Set B.

In option 2c, cyclic switching of N_(TX) chains across N_(SYNC) CCs ofSet-B CCs may be used. In this case, N_(Tx) TX chains may be used ateach SLSS transmission time instance (SLSS TX Time#i) to transmit SLSS.Different cyclically shifted sets of N_(TX) CCs out of N_(SYNC) CCs maybe used at each SLSS transmission time instance for SLSS transmission asit is shown in FIG. 9. Cyclic shift of sync CCs for SLSS transmissionmay enable SLSS transmission across all N_(SYNC) CCs. The specific setof CCs for SLSS transmission may be dependent on SLSS IDs configured perCC and DFN of synchronization resources.

In option 3c, iterative switching of CC groups may be used. In thiscase, groups of TX chains used for SLSS transmission of maximum N_(TX)size may be formed. As it is shown in FIG. 9, two groups of TX chainsmay be created. In the example in FIG. 9, the first group includes 3 TXchains and is used for SLSS transmission at SLSS TX Time#0 and SLSS TXTime#2. The second group includes 2 TX chains and is used for SLSStransmission at SLSS TX Time#1 and SLSS TX Time#3.

In some cases, the retuning of TX chain for SLSS transmission on anotherCC may be in conflict with parallel PSCCH/PSSCH transmission on a givencarrier (depending on switching time). In this case, prioritization ofPSCCH/PSSCH over SLSS/PSBCH transmission on synchronization carriershould be defined. In general, the UE 102 may transmit SLSS only oncomponent carrier(s) with active PSCCH/PSSCH transmissions and do notswitch TX chain solely for SLSS transmission on aggregated CCs.

In some embodiments, a method of sidelink synchronization procedureacross multiple aggregated sidelink component carriers (CCs) maycomprise one or more of: transmission, by the UE 102, of sidelinksynchronization signal (SLSS); reception, by the UE 102 of SLSS;selection, by the UE 102, of a synchronization source and a componentcarrier with high priority synchronization signal to derive transmissiontiming for all CCs using common synchronization reference; selection, bythe UE 102, of a synchronization source and component carrier with highpriority synchronization signal to derive reception timing for all CCsusing common synchronization reference; selection, by the UE 102, ofresources for synchronization signal transmission; and/or other.

In some embodiments, the SLSS transmitter may inform SLSS receiverswhether receiver may propagate particular SLSS timing across aggregatedCCs. In some embodiments, the transmitter may inform the receiver usingadditional field in PSBCH. In some embodiments, the UE 102 may receivePSBCH and may use additional bit in PSBCH to decide, whether receivedSLSS may be propagated across aggregated CCs. In some embodiments, R14PSBCH payload reserved bits may be used for signaling. In someembodiments, R14 sidelink synchronization resources configuration atmultiple carriers may be aligned with R15 sidelink synchronizationresources configuration. In some embodiments, PSBCH payload reservedbits may be preconfigured in a way to allow R15 receivers to propagatetiming across CCs. In some embodiments, same SLSS ID and/or PSBCHcontent fields may be configured across aggregated component carriers.In some embodiments, same SLSS ID and/or PSBCH content fields may beused at all CCs and derived from reference synchronization sourcepropagated across aggregated component carriers. In some embodiments,different SLSS ID or PSBCH content fields may be derived based onpre-configuration information or derived independently based onsynchronization sources detected from each corresponding CCs (e.g.following sync source priority rules). In some embodiments, the UE 102may detect multiple synchronization sources of same priority atdifferent carriers. In some embodiments, the UE 102 may use additionaltie breaking rule(s) to select single synchronization source. In someembodiments, the following information may be used to selectsynchronization source: a PSBCH “SLSS CA Indication Flag”; an SL-RSRPmeasurement; and/or other.

In some embodiments, synchronization carrier reselection may betriggered when at least one of the following events occurs: whencurrently used SLSS is lost at the used CC; when all synchronizationsources which provide GNSS or network timing are lost at the selectedsidelink synchronization CC; when the UE 102 has not detected any SLSSsource at the selected sidelink synchronization CC; and/or other.

In some embodiments, resource reselection may be additionally triggeredto check whether higher priority sidelink synchronization sources existat other Set-B CCs and synchronization carrier should be (re)-selected.In some embodiments, additional synchronization carrier reselection maybe periodically triggered. In some embodiments, a fixed reselectionperiod may be used irrespective of the type of currently used SLSS (i.e.sync source priority). In some embodiments, a reselection period maydepend on synchronization source priority currently used by the UE 102.In some embodiments, a period may be preconfigured by network,predefined by specification or may be determined by UE 102 autonomouslybased on SLSS detection statistics. In some embodiments, the UE 102 mayhave a number of TX chains (N_(Tx)) less than the number ofsynchronization carriers (N_(SYNC)). In some embodiments, the UE 102 mayautonomously select N_(Tx) out of N_(SYNC) CCs and periodically transmitSLSS on selected N_(TX) CCs of the Set B. In some embodiments, the UE102 may autonomously select one out of N_(SYNC) CCs and periodicallytransmit SLSS on selected CC of the Set B. In some embodiments, cyclicswitching of N_(TX) chains across N_(SYNC) CCs of Set-B CCs may be usedto determine the set of active CCs at each SLSS TX time instance. Insome embodiments, iterative switching of a CCs groups may be used todetermine the set of active CCs at each SLSS TX time instance.

The Abstract is provided to comply with 37 C.F.R. Section 1.72(b)requiring an abstract that will allow the reader to ascertain the natureand gist of the technical disclosure. It is submitted with theunderstanding that it will not be used to limit or interpret the scopeor meaning of the claims. The following claims are hereby incorporatedinto the detailed description, with each claim standing on its own as aseparate embodiment.

What is claimed is:
 1. An apparatus of a User Equipment (UE) configuredfor sidelink operation in accordance with a carrier aggregation (CA) ofa plurality of component carriers (CCs), the apparatus comprising: oneor more processors, configured to: select one or more CCs of theplurality of CCs for transmission of a sidelink synchronization signal(SLSS) and a physical sidelink broadcast channel (PSBCH); encode theSLSS for transmission on each of selected CCs in a subframe, wherein theSLSS is for synchronization by other UEs for the sidelink operation;encode the PSBCH for transmission on the selected CCs in the samesubframe used for transmission of the SLSS, wherein the PSBCH is encodedto include a plurality of parameters related to the sidelink operation,wherein the plurality of parameters is to be propagated across all ofthe CCs of the plurality of CCs for the sidelink operation; and encodeone or more physical sidelink shared channels (PSSCHs) for transmissionin accordance with the carrier aggregation, wherein the PSSCHs areencoded for transmission on the plurality of CCs in accordance with theplurality of parameters propagated across the plurality of CCs; performtransmission on the plurality of CCs in accordance with the plurality ofparameters.
 2. The apparatus according to claim 1, wherein the pluralityof parameters related to the sidelink operation includes: apre-configured bandwidth parameter of the selected CCs, a pre-configuredtime-division duplexing (TDD) configuration parameter of the selectedCCs, an in-coverage parameter, and a direct frame number (DFN)parameter.
 3. The apparatus according to claim 2, wherein the one ormore processors are further configured to: determine timingsynchronization for the sidelink operation based on signaling receivedfrom a base station; and derive the in-coverage parameter and the DFNparameter based on the signaling received from the base station.
 4. Theapparatus according to claim 2, wherein the one or more processors arefurther configured to: receive one or more global navigation satellitesystem (GNSS) signals; determine timing synchronization for the sidelinkoperation based on the one or more GNSS signals; and determine the DFNparameter based on the determined timing synchronization for thesidelink operation and a pre-configured DFN offset parameter.
 5. Theapparatus according to claim 2, wherein the one or more processors arefurther configured to: determine timing synchronization for the sidelinkoperation based on signaling received from another UE; and determine theDFN parameter based on signaling received from the other UE.
 6. Theapparatus according to claim 2, wherein: the bandwidth parameterindicates a bandwidth in terms of a number of resource blocks (RBs), theTDD configuration parameter indicates a TDD specific physical channelconfiguration, the in-coverage parameter indicates whether the UE is inEvolved Universal Mobile Telecommunications Service (UMTS) TerrestrialRadio Area Network (E-UTRAN) coverage, and the DFN parameter for theselected CCs indicates a frame number in which the SLSS and SLBCH aretransmitted.
 7. The apparatus according to claim 1, wherein the one ormore processors are further configured to: encode a master informationblock (MIB) for inclusion in the PSBCH, the MIB encoded to include theplurality of parameters related to the sidelink operation.
 8. Theapparatus according to claim 7, wherein: the MIB is aMasterinformationBlock-SL or a MasterInformationBlock-SL-V2X theplurality of parameters related to the sidelink operation includes: apre-configured sl-Bandwidth parameter for the selected CCs, apre-configured tdd-config parameter for the selected CCs, an in-coverageparameter, and a direct frame number (DFN) parameter.
 9. The apparatusaccording to claim 1, wherein the one or more processors are furtherconfigured to: encode the PSBCH to include an SLSS identifier (SLSS-ID)that is to be propagated across all of the CCs of the plurality of CCsfor the sidelink operation.
 10. The apparatus according to claim 1,wherein the one or more processors are further configured to: encode thePSBCH to include an indicator of whether the plurality of parameters isto be propagated across all of the CCs of the plurality of CCs for thesidelink operation.
 11. The apparatus according to claim 1, wherein theone or more processors are further configured to: select the CCs fortransmission of the SLSS and the PSBCH based on a tie-breaking rule thatis based one or more of: an SLSS CA indication flag, and one or moresidelink reference signal received power (SL-RSRP) measurements of theCCs of the plurality of CCs.
 12. The apparatus according to claim 1,wherein the one or more processors are further configured to: determineif reselection of the CC or transmission of the SLSS and the PSBCH is tobe triggered when: a currently used SLSS is lost at a used CC, allsynchronization sources which provide global navigation satellite system(GNSS) or network timing are lost at the selected CC, or the UE has notdetected an SLSS source at the selected CC.
 13. The apparatus accordingto claim 1, wherein the one or more processors are further configuredto: periodically reselect one of the CCs of the plurality of CCs fortransmission of the SLSS and the PSBCH in accordance with a period,wherein the period is preconfigured by a network, predefined by aprotocol, or determined autonomously based on SLSS detection statistics.14. The apparatus according to claim 1, wherein the one or moreprocessors are further configured to: encode the SLSS for transmissionon: the selected CCs, or all of the CCs of a set-B that includes theselected CCs.
 15. The apparatus according to claim 1, wherein: theplurality of CCs includes a synchronization set of CCs, the processingcircuitry further configured to encode the SLSS for transmission inaccordance with one of: selection of a subset of the CCs of thesynchronization set, and periodic transmission of the SLSS on the CCs ofthe subset, selection of one of the CCs of the synchronization set, andperiodic transmission on the selected CC, cyclic switching across theCCs of the synchronization set, or iterative switching of CC groups. 16.The apparatus according to claim 1, wherein: the apparatus includes atransceiver to transmit the SLSS and the PSBCH, and the one or moreprocessors include a baseband processor to encode the SLSS and thePSBCH.
 17. A non-transitory computer-readable storage medium that storesoperations for execution by one or more processors of a User Equipment(UE), the UE configured for sidelink operation on a plurality ofcomponent carriers (CCs), the operations to configure the one or moreprocessors to: select one of the plurality of CCs based on one or moresidelink reference signal received powers (SL-RSRPs); encode, fortransmission on the selected CC, a sidelink synchronization signal(SLSS) to enable synchronization of other UEs for the sidelinkoperation; encode, for transmission on the selected CC, a physicalsidelink broadcast channel (PSBCH) that includes a master informationblock (MIB), encode the MIB to include a plurality of parameters relatedto the sidelink operation, wherein the plurality of parameters is to bepropagated across all of the CCs of the plurality of CCs for thesidelink operation; and encode one or more physical sidelink sharedchannels (PSSCHs) for transmission in accordance with the carrieraggregation, wherein the PSSCHs are encoded for transmission on theplurality of CCs in accordance with the plurality of parameterspropagated across the plurality of CCs.
 18. The non-transitorycomputer-readable storage medium according to claim 17, wherein theplurality of parameters related to the sidelink operation includes: apre-configured bandwidth parameter of the selected CC, a pre-configuredtime-division duplexing (TDD) configuration parameter of the selectedCC, an in-coverage parameter, a direct frame number (DFN) parameter, andone or more reserved bits.
 19. An apparatus of a User Equipment (UE)configured for sidelink operation in accordance with a carrieraggregation (CA) of a plurality of component carriers (CCs), theapparatus comprising: one or more processors, configured to: select oneof the plurality of CCs; encode a sidelink synchronization signal (SLSS)for transmission on the selected CC; encode a physical sidelinkbroadcast channel (PSBCH) for transmission on the selected CC, whereinthe PSBCH is encoded to include a plurality of parameters related to thesidelink operation, including one or more of: a bandwidth parameter ofthe selected CC, a time-division duplexing (TDD) configuration parameterof the selected CC, an in-coverage parameter, and a direct frame number(DFN) parameter, wherein the plurality of parameters is to be propagatedacross all of the CCs of the plurality of CCs for the sidelinkoperation; and encode one or more physical sidelink shared channels(PSSCHs) for transmission in accordance with the carrier aggregation,wherein the PSSCHs are encoded for transmission on the plurality of CCsin accordance with the plurality of parameters propagated across theplurality of CCs.
 20. The apparatus according to claim 19, wherein theone or more processors are further configured to: encode the PSBCH toinclude an SLSS identifier (SLSS-ID) that is to be propagated across allof the CCs of the plurality of CCs for the sidelink operation.